Angled handpiece for dental purposes



lMay 7, 1929.

A. WENDT 1,711,863

AuGL HANDPIECE Fon DENTAL PURPOSES Filed oct. 17, 1927 v K f lnvenfor A Patented May 7, 1929.

-uNlTl-:D STATES PA'rsN'r-i OFFICE.

ADOLF WENDT, OF BERLIN, GERMANY, ASSIGNOR T DEUTSCHE GOLD- UND SILBER- SCHEIDEANSTALT VORMALS ROESSLER, 0F FRANKFORT-ON-THE-MAIN, GER- MANY.

ANGLED HANDPIECE FOR DENTAL PURPOSES.

Application mea october v17, `1927, serial No. 226,787, and 1n Germany october 21, 1926.

This invention relates to an angled hand piece for dental purposes, that is to say, a tool in which the axis of the cutter or bit is at an angle to the axis of the driving shaft, for

5 the purpose of enabling boring or similar operations to becarried out by the tool on parts of the work which could not be operated on, or only operated on with great diliiculty, by the more usual tool having the axisof the cutter or bit in alignment with the axis of the driving shaft.

The invention has particular reference to angled hand pieces, in which the retaining socket or carrier for the bit or tool proper is mounted on rolling bodies in the tool head.

According to 'the present invention the retaining socket or carrier for the bit or tool proper is constructed in parts, adapted to be screwed together, and it is also formed with channels or races to provide in conjunction with corresponding channels or races formed in the head, cages for balls or rollers between. the retaining socket or carrier and the head.

The drive' is imparted to the retaining socket or carrier by means of a crown wheel and a pinion meshing therewith, and another feature of the invention consists in that the pinion is mounted on the externally screwthreaded part of the retaining socket or carrier, the inner end of the other or internally screw threaded part of the retaining socket or carrier thus forming an abutment to prevent undue axial movement of the pinion.

The invention further includes the provision of a sleeve, within the retaining socket, to receive the cutter or bit, this sleeve having a conical and split end for cooperation with a conical face formed in a screw-plug,` which is screwed into the adjacent end of the retaining socket, so that by screwing up or unscrewing the plug,its conical face is caused to bear on orl recede from the conical split end of -5 the sleeve and so cause the sleeve to grip the 4 as the case; may be. p

The sleeve may, however, have both ends split and coned, in which case the end remote from the lug cooperates with an inner 'coni-A cal face ormed on the adjacent endof the retaining socket.

cutter or bitinserted therein or to release it,-

Under these conditions when the cutter or bit is cinserted in the socket, and the plug is screwed into the end of said socket, the split ends of the socket are forced inwardly by sliding engagement between the cooperating conical faces at each end bf the socket,

In the drawing a is the head of the tool,

in the form of a sleeve havin a stem in which the driving shaft is mounte This head or sleeve a is formed with two internal ribs b presenting curved or channeled faces, as shown, to form outer races for balls Z.

A retaining socket or tool carrier d is arranged within the head a.`

This retaining'socket d, is formed in two parts f and g, havinv their inner ends screwthreaded for screw-t readed engagement one within the other.

The outer endsof these parts f and g are enlarged or flanged to close the o en ends of the head or sleeve a and they eac present a curved or channeled face, these curved or channeled faces forming inner races for the balls Z. v

It will thus be appreciated that each set of balls is mounted in a cage constituted by the opposed upper and lower races.

The drive is transmitted from a motor bg a crown wheel z' meshing with a pinion which is screwed on the exteriorly threaded vpart-g of the retaining Isocketd and is prevented from undue axial movement by the inner end of the interiorly screw threaded part fof said socket.

A sleeve m is arr-an d inthe retaining socket d to receive the s ank of the tool.

This sleeve, in the example illustrated, is

, slotted at bothl ends as at n and is provided\ operates with a conical :tace 1' formed on a screw 1plug 0', whichl is screwed into. the outer end o the part f, this end having a Screw thread p formed therein yfor, the purpose, g while the conical enlargement t at the other end of the sleeve m co-operates with a conical face u formed in the outer end of the part g i of the retaining socket d.

When the plug o is screwed into the part f its conical face r will bear on the conical end s ofthe sleeve m thus tending by pressure to reduce the diameter of this split end.

At the same time a longitudinal movement will be imparted to the sleeve by this engagement, thus causing the conical end t to slide along the conical face u at the other end of the sleeve, thereby reducing the sleeve in diameter at this other end, which is also split.

On further screwing up of the plug o both split ends of the sleeve will be reduced in diameter thus tightly gripping the shank of a cutter or bit inserted in the sleeve, both at its outer end and towards its inner end.

If preferred only lthe end of the sleeve m adjacent to the plug o may be split and coned so that gripping of the cutter or bit takes place at this end only, the remainder oi the sleeve being plain and serving. to house the shank of the critter or bit.

The reference lettere indicates the openings left by the annular ribs E, to permit of assembly.

It will be readily appreciated that the construction hereinbeforedescribed permits of assembly and dismantling of the device as a whole by merely screwing together or separating by unscrewing the parts f and g constitu'tlng the retaining socket d..

Moreover, by screwing up or unscrewing the parts f and g to effect relative axial dislacement, correct centering of the carrier d 1s effected automatically, the two parts f, g

thereof being adjusted simultaneously.,

It willalso be appreciated that the construction according to the inventiomavoids )tatable arts projecting from the socket so that satis actoryA working with the tool is'ensul-ed.

I claim: c A

1. An angled hand piece for dental purposes comprising a head casing, annular ribs on the interior of said casing, a tool carrier consisting ofy two parts screwed together at their inner ends and arranged in said casing, annular. enlargements at the outer ends of said parts forming said tool carrier, balls be tween the ribs in said casing and the enlarge- `ments: on said carrier for bearing said carrier in said casing, and means to drive said carrier.

2. An angled 'hand piece for. dental purposes comprising a head casing, annular ribs on the interior of said casing, a tool carrier consisting of Vtwo threaded parts screwed together within said casing, annular enlargements at the ends of said parts forming said tool carrier, balls between at least one of said ribs in the casing and its corresponding enlargement on said carrier for bearing said carrier in said casing, a pinion screwed on the externally threaded part otsaid carrier, and means on the driven shaft of the hand piece in meshing engagement ywith said pin ion. f

3. In a hand piece for tools, a hollow, substantially T-shaped casing consisting of a head and ahandle, a pair of annular ribs formed-on the inside of said head, a tool carf rier consistingof two parts, one of said parts having the inner end threaded internally and the other of said parts having an externally threaded inner end, both inner ends having lesser' diameters than the inner diameters of the ribs and hence being adapted to be uinserted from the opposite ends of the casing f head and screwed together, annular enlargements on the outer ends of said parts of the tool carrier, balls disposed between at least one of said enlargements and the correspondving annular` rib, a rotatable member secured upon the inner end of one of'said parts, and driving means within the handle portion of the casing and in engagement with said rotatable. member.

4. An angled hand piece for. dental purposes comprising a hea casin annular projections in the interiorof sai casing, a tool carrier consisting of two parts screwed together arranged in said casing, annular projections at the ends of said parts forming said tool carrier, balls between `said projections in said casing and on said carrier for bearing said carrier in said casing, a sleeve in said carrier, said sleeve being of shorter length than the carrier, axial slots at one end of said sleeve, conical enlargements at said slotted end, a screw plug in one of said parts forming said carrier, a conical itace on said screw plug cooperating with said conical enlargements of said sleeve, a pinion screwed on the externally screwed part of said carl rer, and a wheel meshing with saidpinion and arranged on the driven shaft of the hand piece.

5. An angled hand piecev for dental puroses comprising a head casing, annular projections in the interior of said casing, a tool carrier consisting of two parts screwed together arranged in said casing, annular pro jections at the ends of said parts forming said tool carrier, balls between said projections 1n said casing and on sald carrier for bearing said carrier in said casing, a sleevein said carr1er,'sa1d sleeve being of shorter length than the carrier, axial slots at both'A ends of said sleeve, conical enlargementsv at 130 said slotted ends, a screw plugin one of said screwed on the externally screwed *part of parts forming said carrier, a conical face on said carrier, and a IWheel meshing with said said screw plug cooperating with one of said pinion and arranged on the driven shaft of l0 conical enlargements of said sleeve, a conical the hand piece. face in the other of said parts forming said In testimonywhereof I affix my signature. carrier and cooperating with the other conil cal enlargement of said sleeve, a pinion lADOLF WENDT. 

